Fingertip xgg  monitor utilizing carrier injection for agc

ABSTRACT

AS A MODULATING SIGNAL FOR THE VARIABLE FREQUENCY OSCILLATOR 27 RESULTING IN A FREQUENCY MODULATED SIGNAL AT 28 FOR TRANSMISSION OVER TELEPHONE LINES FOR EXAMPLE, TO A REMOTE MONITORING STATION.   A MASS SCREENING SYSTEM FOR ELECTROCARDIOGRAPHIC ABNORMALITIES FEATURES A CONSTANT 100 HZ. TONE GENERATOR 20 COUPLED TO THE SUBJECTS&#39;&#39; BODY VIA CAPACITIVE ELECTRODE 12 AND A SENSING SYSTEM FOR PICKING UP THE ELECTROCARDIOGRAPHIC SIGNAL-MODIFIED TONE INCLUDING CAPACITIVE ELECTRODE 11, AMPLIFIER 21, 60 CYCLE FILTER 22, AMPLIFIER 23 AND 60 CYCLE FILTER 24. THE GAIN OF AMPLIFIER 23 IS AUTOMATICALLY CONTROLLED BY A FEEDBACK LOOP WHICH HAS A FILTER 30 TO ELIMINATE ALL BUT THE TONE WHOSE FLUCTUATING AMPLITUDE IS THEN CONVERTED TO A D.C. CONTROL SIGNAL BY CONVERTER 31 AND INTRODUCED VIA LEAD 32 INTO THE AMPLIFIER TO, ADJUST THE GAIN THEREOF. AT THE OUTPUT OF THE 60 CYCLE FILTER 24, A LOW PASS FILTER 25 IS PROVIDED TO REMOVE THE 100 HZ. TON FROM THE ELECTROCARDIOGRAPHIC INFORMATION. THE INFORMATION IS THEN AMPLIFIED IN AMPLIFIER 26 AND USED

nEEENsivE EEEEicArioN UNITED STATES PATENT ()FFICE Published at the request of the applicant or owner in accordance with the Notice of Dec. 16, 1969, 869 O.G. 687. The abstracts of Defensive Publication applications are identified by distinctly numbered series and are arranged chronologically. The heading of each abstract indicates the number of pages of specification, including claims and sheets of drawings contained in the application as originally filed. The files of these applications are available to the public for inspection and reproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to the merits of alleged invention. The Patent Office makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED JULY 24, 1973 Asc coNiROL FET en us A66 :2: j 7 NOTCH flMPLlFIER mo";

so H' 24 EL TRO 25 LOW PASS AMP vco OUT 18 I 2 we a; aouz l GENERATOR A mass screening system for electrocardiographic abnormalities features a constant 100 Hz. tone generator 26 coupled to the subjects body via capacitive electrode 12 and a sensing system for picking up the electrocardiographic signal-modified tone including capacitive electrode l1, amplifier 21, 6O cycle filters 22, amplifier 23 and 60 cycle filter 24. The gain of amplifier 23 is automatically controlled by a feedback loop which has a filter 30 to eliminate all but the tone whose fluctuating amplitude is then converted to a DC. control signal by converter 31 and introduced via lead 32 into the amplifier to adjust the gain thereof. At the output of the 60 cycle filter 24, a low pass filter 25 is provided to remove the 100 Hz. tone from the electrocardiograph'ic information. The information is then amplified in amplifier 2s and used as a modulating signal for the variable frequency oscillator 27 resulting in a frequency modulated signal at 2.8 for transmission, over telephone lines for example, to a remote monitoring station.

July 24, 1973 w. P. HOLSINGER T912,0l

FINGEIRTIP EGG MONITOR UTILIZING CARRIER INJECTION FOR AGO Filed May 1, 1972 FIG. I

AGC CONTROL q 32 I l- 60 Hz AGC BAND AC uo'rcn AMPLIFIER PASS '7 IOOHE 30 DC I6 60 Hz NOTCH ELECTRODES LOW 7 VPASS AMP vco OUT l8 Z loouz 3oHz l GENERATOR FIG.4

EGEN ZCI ZBODY [ECG 0c EGOHZ 02 ,35 II 20 I2 37 'LoAo FIG-.5 

